If you are prescribing Fluorouracil in ANY form, you owe it to your patients to provide the FULL risks in its use.

Questions to Ask Your Doctor:

  • What chemo drug (or combination of drugs) have been prescribed?  (5-Fluorouracil has several different trade names: Efudex, Fluoroplex, Adrucil, and is administered orally now as Xeloda or Capecitabine, and is even used in a cream form for skin cancer under the name of Carac)   And often times, 5-FU is not administered alone but with a few other drugs as well, such as leucovorin, oxaliplatin, docetaxel, irinotecan, or mitomycin C - depending on the type of cancer.
  • What are the concerns when using 5-FU with any other medications, herbal remedies I may be taking?
  • What are the expected side effects from 5-FU or other prescribed drugs?
  • What is the incidence of severe grade 3-4 toxicity to 5-FU?
  • What is the primary cause of this severe 5-FU associated toxicity?
  • What tests are available to help predict my risk for severe toxicity? To determine if I have low DPD activity?
  • Who should be tested for low DPD activity?
  • Does insurance cover the cost of these tests or how much do they cost?
  • Do you have any experience with a DPD Deficient patient? If so, what was the treatment and outcome?
Printable version of questions for your doctor

Your oncologist may recommend keeping a daily journal of your treatment. This is a very important suggestion both during and after treatment. If you are experiencing symptoms related to Fluorouracil toxicity, it will be helpful to you and others-there seems to be virtually no detailed information on the actual severe side effects. Your efforts can help others in this regard.

Questions to Ask Your Insurance Provider:

  • Are any forms or pretesting for DPD Deficiency covered?
  • What are the allowed costs for the testing?
  • If hospitalization is required for severe toxicity, what is covered?
  • Is your company aware of the cost to pretest versus the cost of unexpected hospitalization?

Family Considerations

This could be an endless time of fear and indecision but it should involve family. Balance trust with fact, get a second opinion, take notes and question anything you are uncomfortable with. Rely on your family physician to be an advocate for your safety.


In our experience and as I understand the current system, since testing is not part of the "Standard of Care" there is not much hope of a legal recourse in the routine use of 5-FU when toxicity is encountered. I am placing the only legal information I have found here for the time being. If you have any new information on this, please contact me.

SUCCESSFUL 5-FU OVERDOSE LAWSUIT sorry, this link has been reported broken. The case was on an approx. 54 year old man in California who was treated with 5-fu for advanced throat cancer. I will post any new information as soon as I can find it, nothing on the web exists right now for “successful 5-fu lawsuits...”


I was contacted recently by this testing lab and have been informed the listed price of DPD Testing may actually be lower. If you read the information on the site, you will notice they have a very thorough background in DPD related genetic studies and the education to support their work. Just as important: ITT Labs is working hard to spread the word and open doors with insurance and doctors to make DPD testing an accepted part of treatment.

Other testing sources. I have not had any direct contact for some time and am not sure of current services/prices. Contact them directly with any questions.

Cheryl’s oncologist used low risk and financial hardship over the holidays as reasons not to order testing.  Decide for yourself if that rationale holds water after the risks and cost we’ve provided on this site.